A Japanese input method usually involves mixed input of Japanese and English, that is, an English character string input by a user contains an English character corresponding to a kana character and an English character corresponding to an English entry; therefore, processing needs to be carried out according to the input English character string, so as to identify the English entry and the kana character in the English character string.
At present, the method of processing an English character string in a Japanese input method is: starting from the first English character of the English character string, using a left-to-right positive matching algorithm to segment the English character string to obtain segmentation results, and then successively matching in an input method lexicon; if a kana character is matched according to a segmentation result, it is determined that the segmentation result is a kana character; and if no kana character is matched according to the segmentation result, it is determined that the segmentation result is an English character.
However, when the input English character string contains Japanese and English, since a kana character corresponding to the English character string is obtained preferentially, a candidate entry of English vocabulary will be lost, thus it is not possible to obtain a valid candidate entry, so that the accuracy of the candidate entry displayed in the display box is low.